The present invention relates to flexible magnets having one side coated with an adhesive that is detachably adhered to a strip backing. More specifically, the present invention relates to an improved set of small flexible magnets having one side that is coated with adhesive and attached to a flexible backing in a strip form and an improved method of manufacturing such magnets.
Sheets of flexible magnetic material detachably attached to a backing by way of an adhesive are known and available. Such available magnets include a piece or section of magnetic substrate with one side being coated with an adhesive. The coated side is then attached to a sheet of backing material, such as wax paper. These magnets are available only in individual or roll form and are not available in a set or group of discreet magnets attached to a common sheet or strip of backing paper which can be stripped and applied automatically with existing equipment.
Prior to the development of the present invention, a plurality of magnets disposed on a single, common backing was unavailable because of difficulties in cutting the magnetic material and stripping away the waste webbing of magnetic material from the backing layer. While, thin magnetic substrates are available and are easily cut by currently available dies, such as pressed dies or roller dies, however, the thin magnetic material itself will adhere to the cutting dies, which are fabricated from metal. The use of non-magnetic or non-metal dies have not solved this problem. Specifically, even if non-magnetic or non-metal material dies are used, the adhesion between the magnetic substrate and the backing strip is inadequate to retain the magnetic material on the backing strip. Hence, the magnetic material will still follow the die as the die moves away from the backing material after the cutting stroke and will therefore be removed from the backing material after cutting. As a result, flexible magnets are provided only in individual form, with individual sheets of backing material attached to the individual dies. A plurality of small flexible magnets disposed on a common backing is currently unavailable. Further, a plurality of small flexible magnets disposed in a single row on a common strip backing is also currently available due to the problem of the magnetic material adhering to the die during the cutting process.
There is a need for small, discreet magnets disposed on common backings in either a strip form or in a sheet form. Such materials would be highly useful for promotional material and would facilitate the automated assembly of promotional material. Accordingly, there is a need for a method of fabricating small, discreet magnets on a common strip backing or a common sheet of backing material.
The above need is addressed by the present invention which provides an improved method of manufacturing a plurality of discreet magnets detachably adhered to a common backing.
One method of the present invention comprises the steps of providing a magnetic substrate comprising a first side that is free of adhesive and a second side that is coated with adhesive and detachably adhered to a common backing. The substrate and backing are passed in front of a die with the first side of the magnetic substrate facing the die. The die is hollow and comprises a cutting edge that faces the first side of the magnetic backing. The cutting edge is shaped so as to define an outline for the magnets to be produced. The die further comprises an interior filled with an internal ejector. The method further includes the step of pressing the cutting edge of the die and the internal ejector against the first side of the magnetic substrate thereby cutting through the magnetic substrate but without cutting through the backing to create a cut magnet disposed on the backing. The method further includes the step of pulling the die away from the cut magnet while maintaining a pressing engagement between the internal ejector and the cut magnet so that the die is pulled away from the cut magnet without the cut magnet being pulled off of the backing. The method further includes the step of pulling the internal ejector away from the cut magnet without pulling the cut magnet off of the backing.
Due to the maintaining of the engagement between the internal ejector and the cut magnet after the magnet is cut by the die and during the pulling away of the die from the cut magnet, the cut magnet maintains its position on the backing without adhering to or being pulled off of the backing by the die. As a result, a plurality of discreet magnets may be formed on a single common backing material, such as a strip backing while using the modified cutting die of the present invention.
In an embodiment, the cut magnet is at least partially surrounded by waste magnetic substrate and the method of the present invention further comprises the step of removing the waste magnetic substrate from the backing.
In an embodiment, the method further comprises the steps of moving the cut magnet laterally away from the die and moving uncut magnetic substrate and backing in front of the die and thereafter repeating the pressing and pulling steps set forth above.
In an embodiment, the internal ejector comprises a compressible material with an outer surface that engages the first surface of the substrate. The outer surface of the internal ejector extends outward from the inside of the die and beyond the cutting edge of the die so that the internal ejector engages the first surface of the magnetic substrate before the cutting edge of the die engages the first surface of the magnetic substrate during the pressing step.
In an embodiment, the internal ejector comprises a resilient material and the outer surface of the internal ejector that engages the first surface of the substrate is disposed within the die so that the cutting edge engages the first surface of the magnetic substrate before the internal ejector engages the first surface of the substrate during the pressing step. However, an engagement between the internal ejector and the first surface of the substrate is maintained as the cutting edge of the die is pulled off of or away from the magnetic substrate.
In an embodiment, the internal ejector comprises an outer surface that is in alignment with the cutting edge of the die.
In an embodiment, the die further comprises an outer stripper that engages the waste magnetic substrate as the die is pulled away from the cut magnet to thereby prevent the waste magnetic substrate from adhering to the die and being pulled off of the backing.
In an embodiment, the internal ejector comprises foam.
In an embodiment, the internal ejector comprises a resilient material such as urethane.
In an embodiment, the present invention comprises an improved strip of flexible magnets detachably adhered to a common backing strip and made in accordance with the methods set forth above.
In an embodiment, the present invention provides an improved sheet of flexible magnets detachably adhered to a common backing sheet and made in accordance with the methods set forth above.
In an embodiment, the method of the present invention is further enhanced by use of a non-metallic die.
In an embodiment, a layer of sheet material is disposed between the first side of the magnetic substrate and the die to reduce the magnetic forces between the magnetic substrate and the die. Such a layer of sheet material may be paper or other suitable layered material that can be easily removed. Further, such a layer of sheet material may also be a layer of vinyl or other suitable polymer that has been printed on the first side of the magnetic substrate. The vinyl layer can carry an artistic or informative message, including a promotional message.
In an embodiment, the step of pressing the cutting edge of the die against the first side of the magnetic substrate is carried out by passing the magnetic substrate between two nip rollers, including an upper nip roller that carries a cutting edge and a lower nip roller that engages the underside of the backing. In an embodiment, the diameter of the rollers is reduced thereby providing less contact between the magnetic substrate and the roller carrying the die and thereby providing a reduced attraction between the magnetic substrate and the die and a reduced need for an ejector system.
In an embodiment, the method of the present invention further may employ the use of a magnetic roller or magnet disposed on an opposing side of the common backing from the cutting die to attract the magnetic substrate in a direction opposite from the cutting die and to thereby reduce the possibility of the magnetic substrate from sticking or otherwise being attracted to the cutting die.
In an embodiment, the magnetic substrate may have a normal polarity with a N/S orientation and, the cutting die has an opposite polarity with respect to the contacting substrate side. Accordingly, engagement of the cutting die against the first side of the magnetic substrate results in the magnetic substrate being magnetically repelled from the cutting die.
In an embodiment, the magnetic substrate is sandwiched between a vinyl film disposed on the first side thereof and a carrier film with adhesive coated on one or both sides of the carrier. if both sides of the carrier are coated, the carrier film, would be sandwiched between the magnetic substrate and a common backing. The method for cutting discreet magnets attached to a common backing is carried out in the same method as described above except that the carrier film is cut by the die. However, the employment of a an adhesive carrier film enhances the strength of the layered structure which facilitates the manufacturing process.
It is therefore an advantage of the present invention to provide an improved method of fabricating peel and strip flexible magnets.
Yet another advantage of the present invention is that it provides a method for manufacturing a plurality of discreet, flexible magnets cut from a common magnetic substrate and disposed in a common backing material.
Yet another advantage of the present invention is that it provides a solution to the problem of magnetic substrates adhering to cutting dies during the step of cutting the magnetic substrate with a cutting die.
And another advantage of the present invention is that it provides a plurality of discreet, flexible magnets detachably adhered to a common backing material as opposed to individual magnets equipped with their own individual backing sheets.